Boiler is losing pressure & faults out daily. I have recharged the expansion vessel for CH which seems ok. I tried to recharge the DHW Expansion vessel but could only hear bubbles in the water tank. Does this mean the vessel bladder has gone? Or is there a bigger problem. Had a plumber out, but no joy - don't like Ariston I was told!! Any advice please. Thanks.

Steve M, September 2009

Can i ask how you I have recharged the expansion vessel for CH is it a bike like valve on the vessell

thanks

toby

toby, December 2010

Hi Steve
Pressure relief valves are notorious for not shutting off once they have been opened - its a big mistake to depressurize things this way. The valve will need to be replaced - simple enough if the access is good. Regarding the expansion vessel, only try to pressurize it with air when the system is empty, at no pressure. Use a bike pump to take it up to 10 psi. If you depress the air schraeder valve and water squirts out, then the expansion vessel is kaput. Hope this helps!

John, September 2009

Thanks John. No leaks in the system, but the overflow pipe is dripping constantly. I have checked the 3 relief valves which seem to be opening when I rotate them, and shutting. (maybe not fully). Also I am unable to get a pressure reading on the expansion vessel when I pump air into it - any ideas?

Steve M, September 2009

A boiler losing pressure means one thing - a leak. However, if there is no apparent leak from the central heating pipes or radiators check that the boiler overflow pipe isn't running outside. If it is, the pressure relief valve isn't shutting off fully.

John, September 2009